[Constraint solver] Merge the two areConservativelyCompatibleArgumentLabels()

The decl-based version is only used by the OverloadChoice-based version
anyway.

Author: DougGregor

lib/Sema/CSSimplify.cpp

@@ -135,34 +135,6 @@ bool constraints::areConservativelyCompatibleArgumentLabels(
     hasCurriedSelf = true;
   }
 
-  return areConservativelyCompatibleArgumentLabels(
-      decl, hasCurriedSelf, labels, hasTrailingClosure);
-}
-
-Expr *constraints::getArgumentLabelTargetExpr(Expr *fn) {
-  // Dig out the function, looking through, parentheses, ?, and !.
-  do {
-    fn = fn->getSemanticsProvidingExpr();
-
-    if (auto force = dyn_cast<ForceValueExpr>(fn)) {
-      fn = force->getSubExpr();
-      continue;
-    }
-
-    if (auto bind = dyn_cast<BindOptionalExpr>(fn)) {
-      fn = bind->getSubExpr();
-      continue;
-    }
-
-    return fn;
-  } while (true);
-}
-
-bool constraints::
-areConservativelyCompatibleArgumentLabels(ValueDecl *decl,
-                                          bool hasCurriedSelf,
-                                          ArrayRef<Identifier> labels,
-                                          bool hasTrailingClosure) {
   const AnyFunctionType *fTy;
 
   if (auto fn = dyn_cast<AbstractFunctionDecl>(decl)) {
@@ -173,7 +145,7 @@ areConservativelyCompatibleArgumentLabels(ValueDecl *decl,
   } else {
     return true;
   }
-  
+
   SmallVector<AnyFunctionType::Param, 8> argInfos;
   for (auto argLabel : labels) {
     argInfos.push_back(AnyFunctionType::Param(Type(), argLabel, {}));
@@ -184,7 +156,7 @@ areConservativelyCompatibleArgumentLabels(ValueDecl *decl,
     levelTy = levelTy->getResult()->getAs<AnyFunctionType>();
     assert(levelTy && "Parameter list curry level does not match type");
   }
-  
+
   auto params = levelTy->getParams();
   SmallBitVector defaultMap =
     computeDefaultMap(params, decl, hasCurriedSelf);
@@ -198,6 +170,25 @@ areConservativelyCompatibleArgumentLabels(ValueDecl *decl,
                              listener, unusedParamBindings);
 }
 
+Expr *constraints::getArgumentLabelTargetExpr(Expr *fn) {
+  // Dig out the function, looking through, parentheses, ?, and !.
+  do {
+    fn = fn->getSemanticsProvidingExpr();
+
+    if (auto force = dyn_cast<ForceValueExpr>(fn)) {
+      fn = force->getSubExpr();
+      continue;
+    }
+
+    if (auto bind = dyn_cast<BindOptionalExpr>(fn)) {
+      fn = bind->getSubExpr();
+      continue;
+    }
+
+    return fn;
+  } while (true);
+}
+
 /// Determine the default type-matching options to use when decomposing a
 /// constraint into smaller constraints.
 static ConstraintSystem::TypeMatchOptions getDefaultDecompositionOptions(

lib/Sema/ConstraintSystem.h

@@ -3548,14 +3548,6 @@ matchCallArguments(ConstraintSystem &cs,
 /// subscript, etc.), find the underlying target expression.
 Expr *getArgumentLabelTargetExpr(Expr *fn);
 
-/// Attempt to prove that arguments with the given labels at the
-/// given parameter depth cannot be used with the given value.
-/// If this cannot be proven, conservatively returns true.
-bool areConservativelyCompatibleArgumentLabels(ValueDecl *decl,
-                                               bool hasCurriedSelf,
-                                               ArrayRef<Identifier> labels,
-                                               bool hasTrailingClosure);
-
 /// Attempt to prove that arguments with the given labels at the
 /// given parameter depth cannot be used with the given value.
 /// If this cannot be proven, conservatively returns true.